# patient zero
## English
### Alternative forms

* patient 0

### Etymology

Originally patient O (standing for out of California), referring to Gaëtan Dugas, a superspreader of AIDS who was at the time erroneously believed to have introduced the virus to the United States. The letter O was later misinterpreted as a zero.

### Noun

patient zero (plural patient zeros or patient zeroes or patients zero)
* (epidemiology) The initial patient in the population of an epidemiological investigation.
    Synonym: index patient
    Hypernym: patient
    Coordinate terms: proband (in genetic investigations); index case (loosely synonymous); patient under investigation
** 2005, John De Graaf, David Wann, Thomas H. Naylor, Redefining Progress, Affluenza: the all-consuming epidemic, 2nd illustrated edition, Berrett-Koehler Publishers, →ISBN, page 128:When epidemiologists trace the evolution of a disease, they look for the first individual known to have contracted it, who is given the inglorious lavel "Patient Zero". For example, the official Patient Zero for the AIDS epidemic was a South African man who died in 1959 (though it is suspected that the disease originated as early as the 1920s.
** 2008, Alistair McCartney, The end of the World book: a novel, Terrace Books, →ISBN, page 298:When I think of Gaëtan Dugas, the French-Canadian flight attendant who paid his first known visit to a New York City bathhouse on October 31, 1980, the man to whom all the city's initial cases of AIDS would be traced back—hence the moniker he was given: patient zero […]
** 2009, Teri Shors, Understanding viruses, illustrated edition, Jones & Bartlett Learning, →ISBN, page 443:The term patient zero refers to the first infected patient in an epidemological investigation that is likely responsible for the spread of a particular infectious disease. Randy Shilts, author of And the band Played On, chronicled Darrow's investigation. It was Shilts who proposed that a homosexual Canadian flight attendant was likely patient zero. The flight attendant admitted to anonymous, unprotected sex with as many as 2,500 partners, even after he developed karposis sarcoma. As research continued, though, earlier cases of AIDS were reported (table I6-2), disproving the patient zero theory.
* (figuratively, informal) The source or origin of something.
** 2013 April 20, “Populist: Items of interest this week”, in Alan Rusbridger, editor, The Guardian‎, London: Guardian News & Media, →ISSN, →OCLC, archived from the original on 2014-10-10:Danny Boyle, patient zero of the zombie revival, reviews The Walking Dead.
** 2016 April 17, Jia Tolentino, “How ’Empowerment’ Became Something for Women to Buy”, in The New York Times‎, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 2023-06-24:Dove, the Patient Zero of empowerment marketing, has lifted its sales to the tune of $1.5 billion with its "#RealBeauty" campaign, cooked up by executives who noticed that few women like to call themselves beautiful and saw in that tragic modesty a great opportunity to raise the profile of the Dove brand.
** 2019 August 26, David A. Graham, “Trump Wants to Nuke His Way Out of Big Problems”, in The Atlantic‎, Washington, D.C.: The Atlantic Monthly Group, →ISSN, →OCLC, archived from the original on 21 April 2021:While hurricane-nuking is the most outlandish example of Trump's search for silver-bullet solutions, patient zero for this approach to governance is Trump's border wall.